The goal of this proposal is to achieve a method to map circuits in the brain using near infrared laser stimulation in the FMRI scanner. By using the laser to focally target 100-500um sized building blocks of cortical function (cortical functional domains), we can selectively activate networks that are functionally linked to the targeted domains. Such a capability will allow us to map non-invasively, without the introduction of electrodes into the brain, functional circuits in the cerebral cortex of the primate. Both local an global connectivity patterns will be examined with fMRI, optical imaging, and electrophysiological methods. Such capability will give us a circuit diagram of how basic cortical building blocks produce specific brain functions in behavior and, in turn, will lead to development of methodologies relevant for neurological, neuropsychiatric, and neuroprosthetic applications. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to achieve a method to map circuits in the brain using near infrared laser stimulation in the FMRI scanner. Said capability wil allow us to map circuits of small 100-500um sized building blocks (functional domains) in the cerebral cortex of the primate without the introduction of electrodes into the brain, and provide a circuit diagram of how basic cortical building blocks produce specific brain functions. This knowledge will be relevant for human neurological, neuropsychiatric, and neuroprosthetic applications, which in turn, will lead to development of methodologies that target these building blocks.